Abstract

The Young’s modulus, density, and thickness of a polycrystallinesilicon layer deposited on a silicon wafer covered with a -thick silicon-oxide interface layer were measured using projection masks to generate surface acoustic waves(SAWs) with higher harmonics approaching . The propagating SAW train was detected with a laser probe-beam-deflection setup. The characteristic strongly nonlinear dispersion effect allowed the simultaneous extraction of several unknown film properties. The dispersion was described theoretically by the boundary element method model. A Young’s modulus of , a density of , and a film thickness of were determined for the polycrystallinesilicon film.